The invention relates to a transfer plant, especially for loading and unloading containers from container ships at seaports, with a vertical support which is propped up at the land side and on which a horizontal extension arm is braced, which protrudes across the ship that is to be unloaded on the sea side and along which a horizontal conveying device can travel, which cooperates with hoisting and lowering devices that pick up and put down the containers, being arranged at the land and sea side and also on the horizontal extension arm.
The invention also relates to a method for loading and unloading containers from container ships at seaports, making use of the aforesaid transfer plant.
A container transfer plant with the above described features is known, for example, from DE 40 40 072 A1. The known solution attempts to reduce as much as possible the lost time during the loading and unloading of container ships, which arises at full extension of the hoisting distance during the loading and unloading of the containers. It was recognized that the handling rate of a known system can be considerably abbreviated by appropriately shortening the hoisting and lowering distances.
The problem is solved in the state of the art by using a transport car for the heavy horizontal conveying in such a loading bridge, whose carrying platform is adjustable in height due to lengthwise adjustable carrying elements, so that the carrying platform can be adjusted optimally to the heights of the load transfer.
However, the hoisting and lowering events represent only one of many lost times, and a prime criterion for the handling capacity of the container bridge is first and foremost the duration of a load alternation of the crane trolleys. With increasing size of ship and, thus, increasing width of ship, the sea-side extension arm and thus the horizontal travel distance of the trolleys becomes increasingly longer, and this cannot be balanced out by higher speeds of travel of the trolleys. The maximum trolley travel speeds currently achieved in container bridges of around 4 m/s are on the order of magnitude just within the capabilities of the crane operators; any further increase in trolley speed is hardly feasible.